1 files changed, 127 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mcheck/mce-inject.c b/arch/x86/kernel/cpu/mcheck/mce-inject.c
new file mode 100644
index 000000000000..a3a235a53f09
--- /dev/null
+++ b/arch/x86/kernel/cpu/mcheck/mce-inject.c
@@ -0,0 +1,127 @@
+/*
+ * Machine check injection support.
+ * Copyright 2008 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ *
+ * Authors:
+ * Andi Kleen
+ * Ying Huang
+ */
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/smp.h>
+#include <asm/mce.h>
+
+/* Update fake mce registers on current CPU. */
+static void inject_mce(struct mce *m)
+{
+        struct mce *i = &per_cpu(injectm, m->extcpu);
+
+        /* Make sure noone reads partially written injectm */
+        i->finished = 0;
+        mb();
+        m->finished = 0;
+        /* First set the fields after finished */
+        i->extcpu = m->extcpu;
+        mb();
+        /* Now write record in order, finished last (except above) */
+        memcpy(i, m, sizeof(struct mce));
+        /* Finally activate it */
+        mb();
+        i->finished = 1;
+}
+
+struct delayed_mce {
+        struct timer_list timer;
+        struct mce m;
+};
+
+/* Inject mce on current CPU */
+static void raise_mce(unsigned long data)
+{
+        struct delayed_mce *dm = (struct delayed_mce *)data;
+        struct mce *m = &dm->m;
+        int cpu = m->extcpu;
+
+        inject_mce(m);
+        if (m->status & MCI_STATUS_UC) {
+                struct pt_regs regs;
+                memset(&regs, 0, sizeof(struct pt_regs));
+                regs.ip = m->ip;
+                regs.cs = m->cs;
+                printk(KERN_INFO "Triggering MCE exception on CPU %d\n", cpu);
+                do_machine_check(&regs, 0);
+                printk(KERN_INFO "MCE exception done on CPU %d\n", cpu);
+        } else {
+                mce_banks_t b;
+                memset(&b, 0xff, sizeof(mce_banks_t));
+                printk(KERN_INFO "Starting machine check poll CPU %d\n", cpu);
+                machine_check_poll(0, &b);
+                mce_notify_irq();
+                printk(KERN_INFO "Finished machine check poll on CPU %d\n",
+                       cpu);
+        }
+        kfree(dm);
+}
+
+/* Error injection interface */
+static ssize_t mce_write(struct file *filp, const char __user *ubuf,
+                         size_t usize, loff_t *off)
+{
+        struct delayed_mce *dm;
+        struct mce m;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+        /*
+         * There are some cases where real MSR reads could slip
+         * through.
+         */
+        if (!boot_cpu_has(X86_FEATURE_MCE) || !boot_cpu_has(X86_FEATURE_MCA))
+                return -EIO;
+
+        if ((unsigned long)usize > sizeof(struct mce))
+                usize = sizeof(struct mce);
+        if (copy_from_user(&m, ubuf, usize))
+                return -EFAULT;
+
+        if (m.extcpu >= num_possible_cpus() || !cpu_online(m.extcpu))
+                return -EINVAL;
+
+        dm = kmalloc(sizeof(struct delayed_mce), GFP_KERNEL);
+        if (!dm)
+                return -ENOMEM;
+
+        /*
+         * Need to give user space some time to set everything up,
+         * so do it a jiffie or two later everywhere.
+         * Should we use a hrtimer here for better synchronization?
+         */
+        memcpy(&dm->m, &m, sizeof(struct mce));
+        setup_timer(&dm->timer, raise_mce, (unsigned long)dm);
+        dm->timer.expires = jiffies + 2;
+        add_timer_on(&dm->timer, m.extcpu);
+        return usize;
+}
+
+static int inject_init(void)
+{
+        printk(KERN_INFO "Machine check injector initialized\n");
+        mce_chrdev_ops.write = mce_write;
+        return 0;
+}
+
+module_init(inject_init);
+/*
+ * Cannot tolerate unloading currently because we cannot
+ * guarantee all openers of mce_chrdev will get a reference to us.
+ */
+MODULE_LICENSE("GPL");